The objective of the research project is to elucidate the mechanisms of synthesis, transport and storage of lipoprotein in the chicken, an animal naturally susceptible to hyperlipoproteinemia and arteriosclerosis. The major lipoproteins (HDL and VLDL) in this animal will be isolated and their physical, chemical and immunochemical properties will be studied. Antibodies will be prepared against lipoproteins and radioimmunoassays will be developed. The metabolism of the lipoproteins will be studied in terms of their synthesis in the liver, transport in the blood stream and across the ovarian epithelium, and deposition in the egg yolk, utilizing isotope-immunochemical techniques. The same processes will be studied in in vitro systems. The mRNA's for the lipoproteins will be isolated and their translation in heterologous cell-free systems will be studied. The uptake of the lipoproteins will be examined also in isolated oocytes incubated in vitro. The regulation of these processes by hormonal and local factors will be studied at the cellular and molecular levels. Attempts will also be made to define the mechanism of lipid-binding by the apolipoproteins. The same processes will be examined in the hereditary hyperlipodemic chickens. BIBLIOGRAPHIC REFERENCES: Jackson, R.L., Lin, H.-Y., Chan, L. and Means, A.R. (1977) The Amino Acid Sequence and Phospholipid Binding properties of a Major Apoprotein from Hen Plasma Very Low Density Lipoproteins. J. Biol. Chem. 252:250. Means, A.R. (1976) Mechanisms of Gonadotrophic Hormone Action in the Testis. In: Regulation Mechanisms of Male Reproductive Physiology, Proceedings of the 1975 Brook Lodge Symposium, p. 87.